The present invention relates to a yarn-feeding ring device, and more particularly to a slip-proof elastic yarn-feeding ring device removably mounted on the circumference of a yarn-feeding drum.
In general, the circumference of the conventional yarn-feeding drums include two types: the cage type and the solid type. The yarn-feeding drum of the cage type has an outer circumference formed with plural polished circular rods constructing a fence structure. While the yarn-feeding drum of the solid type has a close outer circumference, both the cage type and solid type yarn-feeding drums have smooth circumferences for a fed yarn to pass therethrough. For example, as shown in FIG. 10, when a yarn 9 is pressed against the smooth circumference of a yarn-feeding drum 1 to be fed via frictional force, by means of a yarn guide 8 mounted on a bracket 5, the yarn 9 is led to enter a belt pressing portion for positive yarn-feeding operation or remove from the same portion to a free smooth portion of the circumference of the yarn-feeding drum for non-feeding operation.
However, when a knitting machine requires numerous yarns and identical yarn-feeding speed with each yarn-feeding drum 1 driven by same yarn-feeding belt 2, the contact area between the yarn-feeding belt 2 and each yarn-feeding drum 1 is greatly reduced and becomes uneven, and therefore, the belt driving speed respective to each yarn 9 is hardly uniform. Furthermore, such speed difference is difficult to be found, and therefore an appropriate adjustment can hardly be exercised to solve the problem, thus making the fabric uneven with poor quality.
Consequently, yarn break ages and operation stop pages occur frequently to reduce the production efficiency.
Concerning the aforesaid problem, a proposal has been used to fit a rubber ring 4 to the whole circumference of the yarn-feeding drum, as shown in FIG. 11. Accordingly, although the abnormal slipping movement existing in positive yarn-feeding operation is effectively eliminated, when a yarn is guided by a yarn guide to leave the belt-pressing portion for non-feeding operation, the yarn can not just slip on the circumference of the yarn-feeding drum without feeding, and a slight irregular yarn-feeding phenomenon still takes place to greatly interfere with the knitting operation, making the fashion and stripe of the fabric confused and uncontrollable.
Therefore, the portion free from the belt pressing force must be smooth. However, if a rubber ring is only fitted to the belt-pressing portion of the circumference of the yarn-feeding drum, the rubber ring will not be fixedly located and creates a nuisance. While if an adhesive is applied to affix the rubber ring to the circumference of the yarn-feeding drum, not only in assembling, the working will be quite difficult to be performed, but also the adhesive applied to the smooth circular rods or the circumference of the yarn-feeding drum is apt to detach therefrom after a period of use and cause troubles.